An object of the present invention is an electro-optical connection module. It can be used especially in the field of connectors for optical transmitter and/or receiver connectors that can be connected to a printed circuit, especially in the field of connectors that convey signals with a frequency of over one gigabit. In the prior art, there is a known electro-optical connector comprising a package that receives one end of an optical fiber, this optical fiber being mounted in such a way that it can be presented so as to face an optical contact of a complementary connector. Furthermore, a connector of this kind has, at the same time, electrical contacts to be connected with complementary electrical contacts of the complementary connector. Should this connector be mounted on a printed circuit, the optical signal conveyed may, if necessary, be converted into an electrical signal in the printed circuit. The value of the invention is that it proposes an electro-optical module with electro-optical conversion means and, at the same time, this module can be mounted on a printed circuit.
In the prior art, there is a known optical connector with a package that receives at least one optical fiber. The optical fiber is positioned through the package in such a way that the end of this optical fiber is presented by the package so as to be placed facing a device complementary to this package. Furthermore, the package is used to accurately position the connector on the complementary device in such a way that the optical signal conveyed by the fiber is oriented towards an optical transmitter and/or receiver of this complementary device. As the case may be, the transmitter/receiver of the complementary device carries out the electro-optical conversion of this optical signal. A connector of this type makes it necessary for the package to be designed very precisely. And the location of the fiber in this package has to also be very precise to ensure the accurate positioning of the fiber before the transmitter/receiver of the complementary device.
Furthermore, in the prior art, there are also known electro-optical connectors comprising a device to receive optical fibers as well as electrical contacts that are connected to electrical cables and are presented so as to be connected with complementary contacts of the complementary device. The electrical contact is generally of the pin or socket type. In this case also, high mounting precision is needed to ensure the accurate positioning of these pins or sockets facing the pins or sockets of the complementary device.
The optical signal is conveyed through the connector. In a first case, the optical signal is sent by the connector towards the printed circuit which then receives this optical signal. In this case, the printed circuit comprises electro-optical conversion means to convert the optical signal received into an electrical signal. This signal can then be conveyed by tracks of the printed circuit to other electronic components of this circuit. In a second case, the optical signal conveyed by the connector is received from the printed circuit. In this case, the printed circuit has sent the optical signal. For example, one of the electronic components of this circuit has sent this signal. Similarly, the printed circuit, using its electro-optical conversion means, has converted the electrical signal into this optical signal. In both examples, the printed circuit implements electro-optical conversion means. Now these means release a quantity of heat that must be discharged to ensure the functioning of the electro-optical conversion. It is then necessary to provide for an additional heat sink on the printed circuit to discharge this heat.
The electro-optical connections of the prior art raise a problem. Indeed, the amount of space taken up by such electro-optical devices is great. Firstly, the optical signal is necessarily transmitted to a printed circuit by means of a connector. Secondly, this optical signal then has to be converted into an electrical signal in the printed circuit. With present-day conditions of miniaturization, the presence of the electro-optical conversion means and of a heat sink in the printed circuit requires a great deal of space. Furthermore, this space requirement of a structure of this kind is all the greater as the connector to be mounted on the printed circuit has to be positioned very precisely in order to make sure that the optical signal is transmitted. The means for aligning the connector entail an additional space requirement.
Furthermore, electronic components that carry out the signal processing and also the electro-optical conversion release much energy. An additional space requirement is created by the necessary presence of a heat sink on the printed circuit.
Consequently, the printed circuit has to be solid and therefore thick and rigid so that it can receive an optical connector, have electrical components and at the same time support a heat sink. The prior art electro-optical connector therefore raises a problem of the space that it takes up.
In order especially to obtain a link which, for the user, is similar to an electrical link, for bit rates of over one gigabit/s, the invention proposes the making of a link based on the use of a pair of modules, each of the modules having an electrical interface that can be dismantled, this pair of modules being connected by an optical channel.
It is an object of the invention to overcome the problem referred to by proposing an electro-optical connector receiving an optical fiber at a first end and having electrical contacts at a second end. Indeed, the electro-optical connection module of the invention comprises means to convert the optical signal emitted by the optical fibers into an electrical signal. Conversely, these conversion means of the connector can also convert an electrical signal received by the electrical contact into an optical signal to be conveyed by the optical fiber. To this end, the connection module comprises a printed circuit comprising a first portion at which the optical signal sent by the optical fiber may be received and then converted into electrical signals. And in one variant, this first portion of a printed circuit may convert an electrical signal into an optical signal, the optical signal being then sent to the optical fiber.
Furthermore, this printed circuit comprises at least one end at which electrical contacts are mounted. Preferably, the circuit comprises two printed circuit ends, positioned on either side of the first printed circuit portion. One advantage of the invention is that it proposes a connection module having a plug shape for connection to a complementary device. For this purpose, the electrical contacts of the printed circuit are brought together at the second end of this connector. Then, the printed circuit comprises at least one flexible printed circuit portion to connect the first end of the printed circuit with the end of this printed circuit. In one preferred example, a first flexible portion is positioned at a first side of the first portion and a second flexible portion is positioned at a second side of the first portion, this second side being opposite to the first side. The two flexible printed circuit ends are then each respectively connected to a flexible portion.
Thus, in a minimum environment, it is proposed to make an optical link between two modules and to carry out a conversion of the electrical signals or the optical signals at the modules, the modules furthermore comprising an electrical connector setting up an electrical connection of this connector with a complementary device, for example on a printed circuit. The optical signal conveyed by the optical fiber is directly converted into an electrical signal at the module. The presence of the conversion means at the module limit the space requirement of the printed circuit designed to receive such a module. Furthermore, this complementary printed circuit undergoes no excessive heating and therefore does not require any specific heat sink. Finally, since the conversion means are present in the module, it becomes easy to replace them when necessary. Indeed, the module can be detached for repairs, whereas replacing these means when they are mounted on the printed circuit for the reception of an optical converter would require the replacement of the entire printed circuit.
The invention therefore relates to an electro-optical connection module comprising a printed circuit, at least one optical component and possibly a control electronic circuit and at least two electrical connectors, characterized in that the printed circuit comprises two flexible printed circuit portions positioned respectively on either side of a rigid portion of this circuit and in that the two flexible printed circuit portions each comprise an end and each have an electrical connector mounted on this end, the ends being brought closer to each other to form an electrical plug.